155193-07-0Relevant articles and documents
Synthesis of Polysubstituted γ-Butenolides via a Radical Pathway: Cyclization of α-Bromo Aluminium Acetals and Comparison with the Cyclization of α-Bromoesters at High Temperature
Bénéteau, Romain,Despiau, Carole F.,Rouaud, Jean-Christophe,Boussonnière, Anne,Silvestre, Virginie,Lebreton, Jacques,Dénès, Fabrice
, p. 11378 - 11386 (2015/08/03)
Polysubstituted butenolides were obtained in good to high yields from α-bromoesters derived from propargyl alcohols by a one-pot reaction involving the radical cyclization of α-bromo aluminium acetals, followed by the oxidation of the resulting cyclic aluminium acetals in an Oppenauer-type process and migration of the exocyclic C-C bond into the α,β-position. Comparison with the direct cyclization of α-bromoesters at high temperature and under high dilution conditions is described. Deuterium-labelling experiments allowed us to uncover "invisible" 1,5-hydrogen atom transfers (1,5-HATs) that occur during these cyclization processes, together with the consequences of the latter in the epimerization of stereogenic centres. Compared to the classical approach, the cyclization of aluminium acetals proved to be highly chemoselective and its efficiency was illustrated by the short total syntheses of optically enriched γ-butenolides isolated from Plagiomnium undulatum and from Kyrtuhrix maculans.
Radical cyclization of α-bromo aluminum acetals onto alkenes and alkynes (radic[al] process): A simple access to γ-lactols and 4-methylene-γ-lactols
Boussonniere, Anne,Beneteau, Romain,Zimmermann, Nicolas,Lebreton, Jacques,Denes, Fabrice
, p. 5613 - 5627 (2011/06/22)
An efficient preparation of γ-lactols and methylene-γ-lactols is described. Highly acid-sensitive lactols are prepared in a concise manner by using a radical cyclization of aluminum acetals. The precursors for the radical reactions are readily prepared fr
Formation of Angularly-Fused Triquinanes by Successive Use of the Pauson-Khand Reaction and Radical Closure
Clive, Derrick L. J.,Cole, Derek C.,Tao, Yong
, p. 1396 - 1406 (2007/10/02)
Angularly-fused triquinanes (see Table 1) are accessible by sequential use of the Pauson-Khand reaction and radical cyclization.The Pauson-Khand step works in the presence of homolyzable bonds, such as C-Br and C-SePh.The method seems best suited to the p